"From January through May Comet ISON brightened hardly at all, remaining stuck at magnitude 16 or 15 and falling nearly two magnitudes behind the early predictions. It became lost in twilight around the end of May and won’t be back in view until the end of August.
So my forecast is that Comet ISON will develop more slowly in the [Northern] autumn morning sky than initially thought. It won’t reach naked-eye detectability until around the 10th of November, about three weeks before rounding the Sun. It will brighten steadily but not exceed 2nd or 3rd magnitude before disappearing into the morning twilight just a week shy of its November 28th perihelion. At that time a short, not particularly bright tail should trail the comet’s intensifying coma.
On perihelion day the head of the comet may spike very briefly to around magnitude –6, brighter than Venus. It might be seen in the daytime sky as a fuzzy point by experienced observers who use great precaution when looking for the comet close to the Sun. This grandeur will persist for only for a matter of hours, as the comet will immediately begin to fade dramatically..."
by John Bortle
http://www.skyandtelescope.com/commu...211408441.html